Abū Dāwūd adds: “We were still in that state until the Prophet ﷺ came out. They repeated to him what they had said, so he replied to them…,” and he mentioned the rest of the report. The chain of transmission is good.

During this very period of waiting the Almighty revealed His words: “They are not all alike among the People of the Book… Allah is fully aware of the God-fearing” (Qur’an 3:113–115).

Ibn Masʿūd (may Allah be pleased with him) said: “The Messenger of Allah ﷺ delayed the ʿIshāʾ prayer. Then he came out to the mosque and found the people waiting for the prayer. He said, ‘There is no follower of any of these religions who remembers Allah at this hour except you.’ Thereupon these verses were sent down: ‘They are not all alike among the People of the Book…’—until he reached, ‘Whatever good they do shall never go unappreciated; and Allah is fully aware of the God-fearing.’” Aḥmad (1/394) recorded it through Shaybān, from ʿĀṣim, from Zur, from Ibn Masʿūd, and its chain is ḥasan (sound).

Even so, he ﷺ did not make this timing obligatory for them because of the hardship involved, as mentioned earlier.

At the same time, he ﷺ would take into account the state of those present, whether they were few or many: sometimes he postponed the prayer, and at other times he performed it early—if he saw them already assembled he led it promptly, but if he saw them slow to gather he delayed it. (Reported by al-Bukhārī, Muslim, Aḥmad 3/369, and al-Ṭiyālisī 124 on the authority of Abū Barzah).